夹心结构水盐运移及分布规律

为探究滴灌条件下地膜覆盖—耕作层—犁底层形成的夹心结构水盐运移及时空分布特征,采用土柱试验,设计耕作层深度为30 cm,设置入渗和蒸发条件下3个灌水量处理(SW1:2 L,SW2:3 L,SW3:5 L)和相同灌水量下3种土体构型处理(SW3:夹心结构;LW3:不覆膜有犁底层;CK:均质土壤).结果表明:入渗过程中,采...

Soil water-salt transport and distribution characteristics in sandwich structure

To explore the soil water-salt transport and temporal-spatial distribution characteristics of the sandwich structure formed by plastic film mulching,plough layer and plough pan under drip irrigation,the design depth of plough layer was set to 30 cm.Three irrigation treatments under infiltration and evaporation conditions(SW1:2 L;SW2:3 L;SW3:5 L)and three soil configuration treatments under the same irrigation volume(SW3:sandwich structure;LW3:no film mulching with plough pan;CK:homogeneous soil)were set.The results show that the soil water content of single plough layer and soil column was compared and analyzed by single factor variance method in the infiltration process.It is found that the soil profile moisture content of three irrigation treatments under sandwich structure has extremely significant difference(P<0.01);there is no significant difference between SW3 treatment and LW3 treatment without plastic film mulching,but there are significant differences between the two treatments and CK treatment(P<0.05).In the sandwich structure,the water infiltration rate is slowed down,the infiltration time is prolonged,and the soil moisture content in the plough layer increases by 22.52%-29.33%.The salt is leached to the plough pan,and the salt leaching effect is inferior to that of the homogeneous soil.In the evaporation process,the inhibition rate of the sandwich structure on soil surface salinity is as high as 88.65%,and the water inhibition rate is 57.65%.The sandwich structure has the optimal effect on inhibition of water and salt evaporation.The research provides a theoretical reference for improving and using saline alkali land and preventing salt accumulation under water-saving conditions.